|Publication number||US6964728 B2|
|Application number||US 10/147,621|
|Publication date||Nov 15, 2005|
|Filing date||May 16, 2002|
|Priority date||May 16, 2002|
|Also published as||US20030213689, WO2003097204A1|
|Publication number||10147621, 147621, US 6964728 B2, US 6964728B2, US-B2-6964728, US6964728 B2, US6964728B2|
|Inventors||Bonnie G. McKinnie, Robert E. Williams, Gary L. Sharp, Alireza M. Dadgar|
|Original Assignee||Mckinnie Bonnie G, Williams Robert E, Sharp Gary L, Dadgar Alireza M|
|Export Citation||BiBTeX, EndNote, RefMan|
|Patent Citations (17), Classifications (16), Legal Events (4)|
|External Links: USPTO, USPTO Assignment, Espacenet|
Distillation is a commonly used method for separating and recovering one distillable liquid from another. There are however instances where a mixture of different liquids contains a dissolved substance tending to precipitate from the distillate and thereby cause pluggage of distillation equipment, such as distillation columns.
This invention is based in part on the discovery that the above pluggage problem can arise when the melting temperature of the dissolved solid component is above the distillation temperature being used to separate one distillable liquid component from one or more residual, non-distilling liquids. Pursuant to this invention, it has been further found that this problem can be avoided by providing to the mixture to be distilled, an adjuvant which forms with the dissolved component a composition that, if isolated, melts at a lower temperature than the distillation temperature to be used for recovering at least one of the distillable liquids from the mixture. The lower melting composition may be a eutectic mixture. However, the proportions of the components in the lower melting composition, whether or not a eutectic mixture, need not be the proportions that form the mixture thereof having the lowest melting temperature—all that is required is that the adjuvant and the higher melting dissolved solid component be proportioned in the solution to form a composition, if isolated, having a melting temperature below that of the distillation temperature to be used for recovering one of the distillable liquids from the mixture.
In a preferred embodiment the adjuvant corresponds to at least one dissolved solid component already present in the solution, such as a by-product or other impurity. This avoids introducing into the solution a component that is not already present, albeit at a smaller concentration. Note that if the component were already present in high enough concentration to form the lower melting composition with the dissolved higher melting solid component, the problem would not arise, and there would be no need to provide an additional amount of such component already present in the solution to be distilled.
Other features and advantages of this invention will be still further apparent from the ensuing description, accompanying drawing, and appended claims.
For ease of reference, the following terms are sometimes used hereinafter:
The prime requirements of the distillable mixture are:
The prime requirements of the adjuvant to be used pursuant to this invention are:
Distillations at atmospheric pressure are preferred in any situation permitting use of distillation. However, in conducting the distillation, reduced pressures, or pressures greater than atmospheric, can be employed whenever deemed necessary or desirable.
Various mixtures of distillable liquid components can make up the liquid phase of the distillable mixtures utilized in the practice of this invention, provided at least one of such liquid components is a distillable liquid. More than one such component can be distillable, and in such case the boiling temperature(s) of each distillable component to be removed by distillation from the distillable mixture should be above the temperature at which the lower melting soluble mixture would solidify, if isolated from the distillable mixture. The distillable mixtures can also contain one or more liquid components which are not distillable or which, if distillable, are not intended or planned to be distilled from the original distillable mixture, all provided that no such component will interfere with the formation of the solute mixture that, if isolated, would constitute a lower melting soluble mixture or otherwise interfere with the distillation. Thus the liquid components of the distillable mixture can comprise water and one or more liquid hydrocarbons, ethers, esters, nitrites, amines, amides, ketones, sulfones, sulfoxides, or other organic substances which are liquid at ordinary ambient room temperatures, or a mixture of two or more organic components at least one of which is to be distilled from the other(s). Various reference publications are available to anyone seeking information about such materials. For example, one may refer to CRC Handbook of Chemistry and Physics, 63rd Edition, CRC Press, Inc., Boca Raton, Fla., copyright 1982, for information about physical states, boiling temperatures and solubilities of numerous chemical substances. Other suitable reference works, of course, also exist.
This invention is especially useful in recovering a distillable organic solvent that is dissolved in water where the mixture is a mother liquor remaining after physically removing a solid product formed in that solvent mixture. Non-limiting examples of such water-soluble distillable solvents are alcohols such as ethyl alcohol, propyl alcohol, isopropyl alcohol, and tert-butyl alcohol; ethers such as tetrahydrofuran, 1-ethoxypropane, 2-ethoxypropane, p-dioxane, and m-dioxane; ketones such as acetone and 2-butanone; amides such as N,N-dimethylformamide and N,N-diethylformamide; esters such as methyl formate, methyl glycolate, and methyl acetoacetate; amines such as cyclohexylamine and N-methylcyclohexylamine; and nitrites such as acetonitrile and propionitrile. In mixtures involving water and a distillable organic solvent, it is preferable that the distillable organic solvent boil at a temperature below the boiling temperature of water. But where the water is the distillable liquid, the organic solvent can subsequently be distilled and recovered, leaving a residue of the lower melting soluble mixture.
Numerous compounds exist that can be formed in and remain dissolved in the two or more liquid components referred to above. Thus the dissolved higher melting solid can be any compound that is soluble enough to be dissolved in liquid components of the distillable mixture, that is stable at least up to the distillation temperature to be used (and preferably above that temperature), and that can form a lower melting soluble mixture with the adjuvant.
The adjuvant used will of course depend upon the dissolved higher melting solid present in the distillable mixture. Other than being a solid at ordinary ambient room temperatures, the adjuvant used must have the capability of forming with the dissolved higher melting solid, a dissolved composition having a melting temperature, if isolated, that is below both the melting temperature of the dissolved higher melting solid and the distillation temperature to be used in the distillation to be conducted.
The practice and advantages of this invention will now be illustrated with reference to FIG. 1. It will be seen that the apparatus depicted includes a distillation column 20 into which flows via line 15 a liquid mixture from which a distillable liquid component is to be separated and recovered. Column 20 can be of any conventional type and configuration suitable for effecting the particular separation to be carried out. The vaporized distillate exits from column 20 and is transferred via line 25 to condenser 30. Condenser 30 is cooled by some appropriate cooling medium circulated in line 32. The condensed distillate is transmitted via line 35 to receiver 40 for storage or reuse by means of line 42. Line 10 serves as the feed line for an adjuvant of this invention. Line 22 can be used to remove the lower melting soluble mixture form column 20. Flows in the lines of the system can be effectuated by pumps (not shown).
The liquid mixture in line 15 upstream from the junction of lines 15 and 10, which mixture can originate from any source, contains at least two different liquid components, at least one of which is to be separated and recovered in purified form. For purposes of this illustration, the liquid mixture is a mixture of ethyl alcohol and water, and among the dissolved components is 2,2-propylenebis[4,4′-(2,6-dibromophenol)], the higher melting solid, with a melting temperature of about 180° C., and also smaller amounts of tribromophenols and still smaller amounts of dibromophenols. The dissolved mononuclear tribromophenol has a melting temperature of about 94° C. Column 20 is operated at a temperature of about 110° C. To prevent pluggage of column 20, an adjuvant of this invention, viz., additional tribromophenol dissolved or slurried in ethyl alcohol, is fed via line 10 and thence with the above liquid mixture into column 20 via line 15. The amount of tribromophenol fed into the column is sufficient to produce a mixture with the 2,2-propylenebis[4,4′-(2,6-dibromophenol)] and the mononuclear bromophenols initially present which mixture, if isolated from solution, is in the molten state at less than 110° C. Hence column pluggage, which would occur in the absence of the adjuvant feed, is avoided.
In another embodiment of the invention, described with reference to
Compounds referred to by chemical name or formula anywhere in this document, whether referred to in the singular or plural, are identified as they exist prior to coming into contact with another substance referred to by chemical name or chemical type (e.g., another component, a solvent, or etc.). It matters not what preliminary chemical changes, if any, take place in the resulting mixture or solution, as such changes are the natural result of bringing the specified substances together under the conditions called for pursuant to this disclosure. Also, even though the claims may refer to substances in the present tense (e.g., “comprises”, “is”, etc.), the reference is to the substance as it exists at the time just before it is first contacted, blended or mixed with one or more other substances in accordance with the present disclosure.
All documents referred to herein are incorporated herein in toto as if fully set forth in this document.
This invention is susceptible to considerable variation within the spirit and scope of the appended claims. Therefore the foregoing description is not intended to limit, and should not be construed as limiting, the invention to the particular exemplifications presented hereinabove. Rather, what is intended to be covered is as set forth in the ensuing claims and the equivalents thereof permitted as a matter of law.
|Cited Patent||Filing date||Publication date||Applicant||Title|
|US2165378||Feb 15, 1936||Jul 11, 1939||Distillation Products Inc||Vacuum distillation|
|US3182088 *||May 26, 1961||May 4, 1965||Dow Chemical Co||Method of making a tetrabromobisphenol|
|US3234289 *||May 26, 1961||Feb 8, 1966||Dow Chemical Co||Method of making a tetrabromobisphenol|
|US3347937||Jun 4, 1965||Oct 17, 1967||Hooker Chemical Corp||Continuous process for manufacture of trihalophenols|
|US4302614 *||Feb 11, 1980||Nov 24, 1981||Riedel-De Haen Aktiengesellschaft||2,2-Bis[4-(2,3-dibromopropoxy)-3,5-dibromophenyl]-propane process|
|US4701568 *||Jun 30, 1986||Oct 20, 1987||Ethyl Corporation||Process for preparing tetrabromobisphenol-A|
|US5395994 *||May 19, 1994||Mar 7, 1995||Albemarle Corporation||Method for recovering methanol solvent|
|US5527971||Apr 24, 1995||Jun 18, 1996||Albemarle Corporation||Process for the preparation of tetrabromobisphenol-A|
|US5723690||Oct 30, 1995||Mar 3, 1998||Albemarle Corporation||Process for the preparation of tetrabromobisphenol-A|
|US5847232||Jun 27, 1997||Dec 8, 1998||Albemarle Corporation||Process for the preparation of tetrabromobisphenol-A|
|US6002050||Sep 8, 1998||Dec 14, 1999||Albemarle Corporation||Process for the preparation of tetrabromobisphenol-A|
|US6084136||Jun 11, 1998||Jul 4, 2000||Albmarle Corporation||Process for the preparation of tetrabromobisphenol-A|
|US6084137||Apr 18, 1996||Jul 4, 2000||Albemarle Corporation||Process for the preparation of tetrabromobisphenol-A|
|US6300527||Jul 12, 2000||Oct 9, 2001||Albemarle Corporation||Process for the preparation of tetrabromobisphenol-A|
|GB1049071A||Title not available|
|GB2049452A||Title not available|
|WO1998037046A1 *||Feb 18, 1998||Aug 27, 1998||Great Lakes Chemical Corporation||PROCESS FOR THE MANUFACTURE OF TETRABROMOBISPHENOL-A WITH CO-PRODUCTION OF n-PROPYL BROMIDE|
|U.S. Classification||203/6, 568/890, 203/47, 203/57, 203/38, 203/100, 203/41, 568/913, 568/749, 203/19, 203/DIG.13|
|Cooperative Classification||Y10S203/14, Y10S203/11, B01D3/34|
|Feb 24, 2004||AS||Assignment|
Owner name: ALBEMARLE CORPORATION, VIRGINIA
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:MCKINNIE, BONNIE A.;WILLIAMS, ROBERT E.;SHARP, GARY L.;AND OTHERS;REEL/FRAME:015009/0447;SIGNING DATES FROM 20020508 TO 20020510
|May 25, 2009||REMI||Maintenance fee reminder mailed|
|Nov 15, 2009||LAPS||Lapse for failure to pay maintenance fees|
|Jan 5, 2010||FP||Expired due to failure to pay maintenance fee|
Effective date: 20091115